Solar Power – Inverters

What Are Inverters?

Basically an inverter is a device which converts the electricity from your solar panels to a form that can be used by normal domestic appliances, and lights.

The electricity generated by the solar panels is Direct Current (DC) but the typical home runs on Alternating Current (AC)*.

*It is possible to run a home on DC electricity without an inverter but you will need to buy special appliances, such as those designed for caravan use. The wiring requirements are also quite different!

Types of Inverter Applications

There are three types of inverter applications which all require different types of inverters, which are:

Stand Alone Inverters

These are used for houses that are not connected to the local power grid. The solar panels charge a bank of batteries by Direct Current. When an appliance is switched on the inverter converts the DC electricity from the batteries into AC power.

This is a relatively simple form of inverter, and the system as a whole has the following characteristics:

No power bills.

Unaffected by power cuts.

Initially expensive due to the cost of a large bank of batteries.

You may need an auxiliary power supply such as a generator for long periods with little sunlight.

Grid Tie Inverters

The most common form of inverter these days. The solar panels feed Direct Current into the inverter which converts the electricity into AC power. The power is then used by any appliances that are on, with excess electricity being ‘pushed’ into the grid. (You will be credited for this electricity) If electricity demand greater than the solar panels can provide power is taken from the Grid.

Reduced power bills.

A power cut will result in complete loss of power.

Lowest cost solar power system.

Dual Inverters

Also called Battery Backup Inverters. The solar panels charge a bank of batteries by Direct Current with the batteries providing power to the house in a similar manner to the standalone system. When the batteries are fully charged any excess power is ‘pushed’ into the grid. (You will be credited for this electricity)

This is the most complex and expensive type of inverter, The system as a whole has the following characteristics:

Reduced power bills.

Unaffected by power cuts for several hours (depending on battery capacity).

Mid range cost. Although the inverter is expensive there are typically far fewer batteries than a stand alone system.